Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filedfiledCritical
Priority to JP13152882UpriorityCriticalpatent/JPS5936680U/ja
Publication of JPS5936680UpublicationCriticalpatent/JPS5936680U/ja
Application grantedgrantedCritical
Publication of JPH039431Y2publicationCriticalpatent/JPH039431Y2/ja
Ultrasonic microphone for operating with an accumulated layer of mud over its vibratile surface without change in sensitivity within its prescribed frequency range